#selectables { width:1500px; height:1000px; } 
#selectables div { width:160px; height:25px; padding:5px 0 0 10px; border:1px solid #000; margin:10px 0 0 10px; float:left;}
#selectables div.ui-selecting { border:1px solid #66CC00; }
#selectables div.ui-selected { background:#66CC00; }